JPH01196254A - Preparation of yogurt - Google Patents

Abstract

PURPOSE:To prepare a yogurt having moderate hardness, smooth texture and excellent taste, flavor, palatability, etc., and exhibiting little syneresis, in high workability, by adding a concentrated whey protein free from heat-coagulation tendency as a stabilizer for yogurt. CONSTITUTION:Concentrated whey protein is passed through an ultrafiltration membrane having a fractionation molecular weight of 20,000-100,000 to obtain a concentrated whey protein free from heat-coagulation tendency. The obtained concentrated whey protein is used as a stabilizer singly or in combination with other stabilizer (e.g., agar or gelatin) and mixed with raw materials such as defatted milk, sugar, etc. The mixed raw material is added to a warmed water and the mixture is subjected to homogenization, sterilization, cooling, etc., added with lactobacillus as a starter, fermented and refrigerated to obtain the objective yogurt. Since there is no gelation by cooling or heat-coagulation by thermal sterilization, etc., the yogurt can be prepared in high workability.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to foods, and relates to the industrially advantageous production of yogurt products. In this case, yogurt refers to soft type, hard type, plain type, drink type, and frozen type.

<Prior art> Taking hard type yogurt as an example, the general manufacturing process is as follows. The raw materials include at least 8% skim milk powder, sugar, and other stabilizers such as agar, gelatin, and carrageenan. First, these materials are mixed into warm water. and homogenization (150-20
After a series of operations of sterilization (90 to 95°C, 10 minutes), and cooling (42 to 45°C), lactic acid bacteria etc. are added as a starter and fermentation is carried out. Filling the container is done when the starter is added, and fermentation is stopped at pH 3.8.
Refrigerate. The purpose of adding stabilizers in the formulation is to reduce syneresis of yogurt and give it appropriate elasticity, hardness, and texture. However, traditional stabilizers, namely agar,
Gelatin, carrageenan, etc. have the following drawbacks.

(2) These stabilizers have a high gelation initiation temperature, and depending on the amount added, it is necessary to take measures to prevent gelation, such as constant stirring during the cooling process.

■These stabilizers, together with yogurt, inhibit the release of yogurt's unique and desirable flavor.

■The texture of yogurt made with these stabilizers has the following drawbacks. Gelatin has wet viscoelasticity, but softens at room temperature and has a rough texture. Although agar has hardness, it is a fragile tissue.

Carrageenan has a strong reactivity with proteins and separates, especially under low pH conditions, resulting in rough tissue. The above-mentioned stabilizers have been used singly or in combination, but they are by no means satisfactory.

<Problem to be solved by the invention> Here, whey protein concentrate (hereinafter referred to as WPC) which has no thermocoagulability
) will be adopted. WPC is a byproduct during the production of cheese and casein, and is used for whey, ultrafiltration, concentration,
The method of powdering through a drying process has been established industrially. It is used as a substitute for egg white because it has properties similar to egg white, such as being soluble in water and coagulating when heated. One possible way to eliminate the thermal coagulability of WPC is to denature the proteins in the WPC components by changing temperature, pH, etc., but in most cases, this will result in a decrease in solubility in water, an increase in viscosity, and a decrease in milk content. It cannot be used in practice because it does not cause any off-flavor or odor other than sweet flavor.

Here, by adjusting the permeable membrane for ultrafiltration, it is possible to obtain WPC that is protein-undenatured but not thermocoagulable, similar to conventional WPC. The permeable membrane for ultrafiltration used herein refers to a semipermeable membrane with a molecular weight cut-off of 20,000 to 100,000.

The WPC thus obtained differs from conventional WPC only in the presence or absence of heat coagulation, and has no differences in solubility in water, flavor, total protein content, etc. When this WPC is used in yogurt, it has the following effects. It can be used as a substitute for stabilizers such as agar, gelatin, carrageenan, and the main ingredient milk and dairy products such as city milk and skim milk powder, and the amount used is 15% of the total amount of yog/L/).
% (weight I%), preferably 1 to 8%. Also, Dai.

In addition to using it alone as an ingredient, it also has the following effects and benefits when used in combination with the above stabilizers, milk, and dairy products.

■It gives Yogurshito an appropriate hardness, and the hardness can be freely adjusted by adjusting the amount added.

■Yoglucite tissue is extremely smooth. It is preferable because it exhibits a characteristic texture that is clearly different from other stabilizers.

■The amount of water separation decreases.

■The flavor is extremely good, as it is part of the milk component.

■It is easy to work with because it does not gel due to cooling or thermal coagulation occurs even when heated at high temperatures such as in Play F sterilization.

The effects of this invention will be explained below.

(Experiment Example 1) 0 Syneresis Test (Plain Type Yogurt) Each sample was added to city milk while heating it.

(Samples and amounts added are described separately) Homogenization (150 kg/d) at milk temperature of 80°C, sterilization (90 to 95°C)
Add 396 (wt%) of the total amount of lactic acid bacteria Yogur (containing 10/? or more lactic acid bacteria) as a starter and ferment at 40''C.Fermentation is carried out at pH, s. Stop and refrigerate the yogurt.

The syneresis rate of this finished yogurt was examined.

Judgment method) Pour a certain amount of yogurt from each sample into a fine-mesh strainer. Cut each specimen using a knife in the same way (about 11 squares). At this time, the amount of water flowing out for 5 minutes was measured to determine the water separation rate.

(Experiment Example 2) All ingredients are thoroughly stirred and mixed. (For prescriptions, refer separately) Homogenization (150#g/d), Sterilization (9o~95°c11
0 min) and cool (40°C). Lactic acid bacteria yogurt (
3% of the total amount of yoghurt/L/) is added as a starter (containing 10 or more lactic acid bacteria), this is filled into the same type of container, and fermented in a thermostatic chamber (40'C).

Fermentation is stopped at pH 3.8 and refrigerated. Using this yogurt, the following items were investigated.

(Prescription) (Results) Judgment method) 0 Gel strength: Measured in the container using a card meter manufactured by Ion Denki.

0 sag at room temperature: Refers to the softening of yogurt at room temperature, and was judged sensually.

The above symbol does not soften ◎〉○〉△〉×Softens 0 Other sensory tests The above symbol has the following: Smoothness: Smooth ◎〉○〉△〉×Rough Hardness: Hard A>B>C>
D Soft flavor: Good A>B>C> D Bad (Experiment Example 3) ◎Gelation test Add the sample (separately) to 8% skim milk powder and dilute the total volume to 100% with water.
% solution is used. Heat this solution in a warm bath at 90-95°C.
C1 Sterilize for 10 minutes, leave it standing in a water tank, and observe the state of the solution at each temperature.

The above symbols represent the following:

- Bi-fluid, smooth liquid +: sticky, pasty feeling + gelatinous Example 1 ◎Fruit yogurt 8% skim milk powder, 3% unsalted butter, WPC without heat coagulation
1, 5% to 100% with warm water. These materials were mixed well, heated to 80°C, and homogenized (150 kg/d
), sterilization (90-95°C for 110 minutes), cooling (45°C
)do. Add lactic acid bacteria starter and ferment at 42°C for 4 hours. The pulp of strawberries, keelai, pineapple, etc. was added to this and mixed and stirred to obtain fruit yogurt. This fruit yogurt had a very smooth and spreadable texture with no separation from the fruit, and the flavor was mellow and plump.

Example 2 ◎Frozen yogurt 15% skimmed milk powder, 3% unsalted butter, WP without heat coagulation
Mix 2% C and 8% sugar to 100% with warm water and mix well.
Warm to 0°C. Homogenization (9/d to 150) Sterilization (9/d)
0-95°C for 110 minutes), cooled (45°C), added lactic acid bacteria starter, fermented at 42°C for 5 hours, and then cooled. This is mixed with yogurt base, 65% yogurt paste and 35% fruit syrup, and 0.5% of WPC, which does not coagulate under heat, is added. Freeze this in an ice cream freezer, with an overrun of 70%, -
Cured at 25°C. The frozen yogurt thus produced had a very smooth texture and a good flavor.

Claims (2)

[Claims] (1) A method for producing yogurt, which comprises adding a whey protein concentrate that does not coagulate under heat. (2) The method for producing yogurt according to claim 1, which is obtained by passing a whey protein concentrate through a specific ultrafiltration membrane in order to eliminate thermal coagulation properties.